Dictionary · FIPS PUB 197

The Advanced Encryption Standard specifies a U.S. government-approved cryptographic algorithm that can be used to protect electronic data. The AES algorithm is a symmetric block cipher that can encrypt (encipher) and decrypt (decipher) information. This standard specifies the Rijndael algorithm, a symmetric block cipher that can process data blocks of 128 bits, using cipher keys with lengths of 128, 192, and 256 bits.

Sequence of binary bits that comprise the input, output, State, and Round Key. The length of a sequence is the number of bits it contains. Blocks are also interpreted as arrays of bytes.

Data output from the Cipher or input to the Inverse Cipher.

Series of transformations that converts plaintext to ciphertext using the Cipher Key.

Series of transformations that converts ciphertext to plaintext using the Cipher Key.

Routine used to generate a series of Round Keys from the Cipher Key.

Cryptographic algorithm specified in the Advanced Encryption Standard (AES).

Data input to the Cipher or output from the Inverse Cipher.

Round keys are values derived from the Cipher Key using the Key Expansion routine; they are applied to the State in the Cipher and Inverse Cipher.

Nonlinear substitution table used in several byte substitution transformations and in the Key Expansion routine to perform a one-for-one substitution of a byte value.

Intermediate Cipher result that can be pictured as a rectangular array of bytes.